MOLECULAR-GENETIC PROPERTIES OF VIBRIO CHOLERAE EL TOR STRAINS CIRCULATING IN AFRICA.

The review contains some brief information on cholera epidemics in Africa. Based on the results of the whole genome sequencing of 30 clinical strains isolated in Africa in different periods of the 7th cholera pandemic (1985-2012), extensive genetic diversity has been revealed. It is demonstrated that at present cholera epidemics in Africa are caused by new variants of the agent, which emerged in South- Eastern Asia in consequence of not only new genes acquisition, but also genome alterations of pandemicity and pathogenicity islands.

[EFFECT OF OSMOTIC AND OXIDATIVE STRESS ON STRAINS OF GENOVARIANTS OF VIBRIO CHOLERAE EL TOR BIOVAR].

Aim: Study the effect of osmotic and oxidative stress on survivability and changes in phenotypic and genetic properties of strains of genovariants of V. cholerae El Tor biovar.

Materials And Methods: 22 strains of V.

[EVALUATION OF FUNCTIONAL FEATURES AND STRESS RESISTANCE OF ISOGENIC TOXIGENIC AND NON-TOXIGENIC BIOVAR EL TOR VIBRIO CHOLERAE STRAINS].

Aim: Comparative evaluation of functional features of toxigenic biovar El Tor Vibrio cholerae strains and their spontaneous non-toxigenic mutants and study of their resistance to saline and oxidative stress.

Materials And Methods: 8 biovar El Tor V. cholerae strains were studied: 4 clinical strains isolated in 1970 from patients in Astrakhan and 4 spontaneous non-toxigenic mutants of these strains that have lost cholera toxin genes as a result of residence in river water at the temperature of 25°C.

[ISOLATION OF ANTIBIOTICS RESISTANCE GENES IN VIBRIO CHOLERAE O1 AND O139 SEROGROUP STRAINS].

Aim: Determination of sensitivity of V. cholerae O1 serogroup El Tor biovar and O139 serogroup strains to antibiotics and determination of the presence of antibiotics resistance genes in their genome.

Materials And Methods: The studies were carried out in 75 V.

[Algorithm of toxigenic genetically altered Vibrio cholerae El Tor biovar strain identification].

Aim: Development of an algorithm of genetically altered Vibrio cholerae biovar El Tor strai identification that ensures determination of serogroup, serovar and biovar of the studied isolate based on pheno- and genotypic properties, detection of genetically altered cholera El Tor causative agents, their differentiation by epidemic potential as well as evaluation of variability of key pathogenicity genes.

Materials And Methods: Complex analysis of 28 natural V. cholerae strains was carried out by using traditional microbiological methods, PCR and fragmentary sequencing.